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From: Christoph Hellwig <hch@lst.de>
To: "T.J. Mercier" <tjmercier@google.com>
Cc: Christoph Hellwig <hch@lst.de>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Robin Murphy <robin.murphy@arm.com>,
	isaacmanjarres@google.com,
	Catalin Marinas <catalin.marinas@arm.com>,
	iommu@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] dma-direct: Set SG_DMA_SWIOTLB flag for dma-direct
Date: Wed, 8 May 2024 13:33:53 +0200	[thread overview]
Message-ID: <20240508113353.GA31529@lst.de> (raw)
In-Reply-To: <CABdmKX3PgcXaRUH3L7OV+POMiMd5L6pEF4fLXYPgfmQUNu_trg@mail.gmail.com>

On Tue, May 07, 2024 at 01:07:25PM -0700, T.J. Mercier wrote:
> On Mon, May 6, 2024 at 10:43???PM Christoph Hellwig <hch@lst.de> wrote:
> >
> > On Mon, May 06, 2024 at 09:39:53AM -0700, T.J. Mercier wrote:
> > > > You should not check, you simply must handle it by doing the proper
> > > > DMA API based ownership management.
> > >
> > > That doesn't really work for uncached buffers.
> >
> > What uncached buffers?
> 
> For example these ones:
> https://android.googlesource.com/kernel/common/+/refs/heads/android-mainline/drivers/dma-buf/heaps/system_heap.c#141

Whatever that code is doing is probably not upstream because it's too
broken to live.


  reply	other threads:[~2024-05-08 11:33 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-03 18:37 [PATCH] dma-direct: Set SG_DMA_SWIOTLB flag for dma-direct T.J. Mercier
2024-05-04  8:53 ` Petr Tesařík
2024-05-09 13:28   ` Robin Murphy
2024-05-06  5:29 ` Christoph Hellwig
2024-05-06 16:00   ` T.J. Mercier
2024-05-06 16:02     ` Christoph Hellwig
2024-05-06 16:10       ` T.J. Mercier
2024-05-06 16:19         ` Christoph Hellwig
2024-05-06 16:39           ` T.J. Mercier
2024-05-07  5:43             ` Christoph Hellwig
2024-05-07 20:07               ` T.J. Mercier
2024-05-08 11:33                 ` Christoph Hellwig [this message]
2024-05-09 12:54                   ` Robin Murphy
2024-05-09 18:26                     ` T.J. Mercier
2024-05-08 17:19                 ` Catalin Marinas
2024-05-08 20:14                   ` T.J. Mercier
2024-05-09  7:49                     ` Catalin Marinas
2024-05-09 13:06                       ` Christoph Hellwig
2024-05-09 18:32                         ` T.J. Mercier

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